The present invention relates to fittings for pipes of the type made of rubber, plastic material, multilayered, etc., and more specifically to fittings for the connection of pipes by means of pressing.
Such fittings may be linear, elbow-shaped or T-shaped, with or without a male or female threaded section, but they do usually have at least one rubber-holder section to connect a pipe there. The rubber-holder section has a grooved outer surface and usually accommodates two toric seals (O-rings) that are spaced in parallel to one another.
A pipe is connected to the fitting by arranging a bushing around the pipe, threading the rubber holder in the pipe and contracting the outer bushing with a pressing tool until the pipe presses and locks onto the rubber holder.
However, the fittings of the prior-art type are not without drawbacks. In these fittings, the sealing between the connected rubber holder and pipe depends on the pair of toric seals, which are premounted on the rubber holder. But when the bushing has been compressed, the two seals undergo a very strong deflection in the related seats. These seals themselves therefore guarantee an excellent sealing, but if they are stressed by a rotation of the pipe around its own axis (an operation which usually is carried out by the plumber upon the installation of the pipe), they run the risk of damage or even breaks which clearly may cause the loss of tightness of the seal, as has already occurred and can be proven.